Fig. 4. An LD prime elicits CD8⁺ T cell responses with intrinsically superior anamnestic capacity.

CD45.2⁺ mice were immunized intramuscularly with 10⁶ or 10⁹ PFU of Ad5-SARS-CoV-2 spike, and at day 28, splenic CD8⁺ T cells were MACS-sorted. Subsequently, live K^b VL8⁺ CD8⁺ T cells were FACS-sorted to ~99% purity, and numbers were normalized for adoptive transfer into CD45.1⁺ recipient mice. (A) Experimental design for evaluating secondary expansion of donor CD8⁺ T cells. (B) Representative FACS plots showing the frequencies of donor CD8⁺ T cells in PBMCs after boosting (gated from live CD8⁺ T cells). (C) Summary of donor-derived CD8⁺ T cells in PBMCs. (D) Summary of donor-derived CD8⁺ T cells in spleen. Data from (B) to (D) are from day 14 after boost. Data are from two experiments, each with n = 5 per group. All data are shown. Indicated P value was determined by nonparametric (Mann-Whitney U) test.